This is going to go round in circles for the foreseeable future, because you seem to be having the same scripted conversation (either internal or with him), every time you suspect infidelity.
You tell us that you spent years in relationships with abusive men and then you became abusive yourself and had affairs involving what you admit were elaborate deceptions. That whatever issues these men had, they were not unfaithful and you were therefore able to believe that you were truly adored. Well, that's the first flaw in your belief system, but it's one that many women have, that fidelity equates to adoration.
You say that even if there were no concerns about fidelity in your current relationship, you suspect you would still have concerns, because you don't feel adored in the way you have been used to in the past. Perhaps too, because you haven't yet had an urge yourself to be unfaithful in this relationship, you are placing it on too high a pedestal?
I'd urge you to reframe your former partners' adoration and see those relationships with more clarity. Just because they weren't unfaithful does not mean they adored you and loved you. Their other behaviours suggest that they didn't at all.
Now on to this relationship. You are not married and got together in a rush, precipitated by the birth of your child. It just doesn't sound as though you have ever had an honest dialogue about your feelings for eachother, or the challenges of remaining faithful to one another, which is all the more bizarre given your pasts.
The only time you seem to have a conversation about your feelings towards one another or fidelity is when you suspect he is being unfaithful. Because you equate adoration with fidelity, I wonder whether this explains your resistance to what seems to be staring you in the face? That if you found incontrovertible proof of infidelity, that would mean you had to finally face up to the fact that he doesn't adore you?
I think you've deleted a more recent thread or possibly name-changed for that one. By my recollection, 4 years ago you found a condom in his washbag after an overnight work do. He told you that he had put it in there "out of force of habit" and you bargained that one away, subsuming the nagging doubt that the fidelity that night had been controlled by the absence of a willing partner.
Then one of your own condoms went missing and you uncovered meetings with a friend who was so unknown to you that it didn't occur to you that he had a unisex name. I believe there was a deleted thread/name-change after that with more suspicions and now we've got this one, involving an attached father going out of the house with a condom in his pocket. Unless I am very much mistaken, I believe the last incident involved a condom about his person and he managed to persuade you that he was carrying it around to use with you, if an opportunity arose, outside of the bedroom.
This latest incident would be suspicious alone, but when it is the third or fourth condom-related incident, it beggars belief that your partner doesn't want to have sex with someone else.
Dittany is right that the infidelity isn't the only problem here. Your lack of awareness about his feelings for you is one of the biggest elephants in the room, but you are focusing on infidelity and then ignoring the evidence, perhaps because you don't want to acknowledge the bigger issue and because you continually confuse fidelity with adoration.
You are right that at the point of infidelity, an unfaithful partner does not adore his primary partner, either by design or because of longstanding detachment, but being faithful does not equate to love and adoration.